Abstract: 【OBJECTIVE】The antifungal activities of greseofulvin The antifungal activities of greseofulvin against ten isolates of Fusarium oxysporum, pathogen of crop Fusarium wilt disease were investigated with an aim to extend the application of griseofulvin for controlling the disease. The antifungal activities were determined in a set of inhibition ratio and inhibition ring tests with the ten isolations of F. oxysporum as indicators, which were isolated from oriental melon, cucumber, water melon, pepper and tomato. The effect of griseofulvin on the growth of the isolations was observed under microscopes. The results revealed that the ten isolations presented significantly different but high sensibility to griseofulvin. The half-inhibitory concentration (IC50) values of greseofulvin against the fungi were calculated as 0.42-2.81 mM. Treated with 4 mM griseofulvin, F. oxysporum was found to be induced degenerative changes of hyphal morphology. The study indicated that griseofulvin may be a new promising biological agent or a lead compound for novel antifungal agent for controlling Fusarium wilt disease.